![]() ![]() The manikin head always became hotter, but adding the straight-haired wig cut that heat gain by more than half compared to a bare head. Under a simulated sun beaming down at 86 degrees Fahrenheit, the starkest difference in heat was between no hair and hair. Proceedings of the National Academy of Sciences Researchers tested three different wigs to see the effects of hair on head temperature. To better understand how hair affected the temperature of the head, Lasisi and her colleagues placed three different wigs or no wig on a research manikin, called a “thermal manikin.” The manikin was heated to a body temperature of 95 degrees, according to National Geographic, and placed under hot lights in a climate-controlled wind tunnel. The scientists measured the temperature on the manikin’s head when covered with no wig and human hair wigs that had straight strands, loose curls or tight coils-which were similar in thickness and color. “The brain is a large and very heat-sensitive organ that also generates a lot of heat,“ says Penn State anthropologist Tina Lasisi to National Geographic’s Tom Metcalfe. “So we figured, evolutionarily, this could be important-especially in a period of time when we see the brain size of our species growing.” Shielding the head from heat could have been crucial for early hominid ancestors living in Africa under the equatorial sun. ![]() A new study published this month in Proceedings of the National Academy of Sciences suggests these strands coming out of our heads may have evolved to stop our ancestors’ large brains from overheating, with curly hair cooling more. Scientists have long wondered why humans' scalps are covered in hair even though we are far less hairy elsewhere. ![]()
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